Method and apparatus of cleaning a pool



April 14, 1970 w. o. BAKER METHOD AND APPARATUS OF CLEANING A POOL 3Sheets-Sheet 1 Filed Aug. 26, 1968 F16.

m' lea I a QFILTER I-65 4 INVENTOR.

W/LL/AM 0. BAKER ATTORNEYS.

April 14, 1970 w. o. BAKER METHOD AND APPARATUS OF CLEANING A POOL 5Sheets-Sheet 2 Filed Aug. 26, 1968 INVENTOR. WILL/AM 0. fill/(2 BY 2;

ATTORNEYS.

April 14, 1970 o. BAKER 3,506,489

METHOD AND APPARATUS 0F CLEANING A POOL Filed Aug. 26, 1968 3Sheets-Sheet 5 INVENTOR. WILL/AM O. Ell/(2 ATTORNEYS.

United States Patent 3,506,489 METHOD AND APPARATUS OF CLEANING A POOLWilliam 0. Baker, West Covina, Califl, assignor to Swimquip, Inc., ElMonte, Calif., a corporation of California Continuation-impart ofapplication Ser. No. 637,608, May 10, 1967, which is acontinuation-in-part of application Ser. No. 507,607, Oct. 22, 1965,which in turn is a continuation-in-part of application Ser. No. 291,885,July 1, 1963. This application Aug. 26, 1968, Ser. No. 770,133

Int. Cl. B08b 7/04 US. Cl. 134-10 13 Claims ABSTRACT OF THE DISCLOSUREIndividual ones of a plurality of jet streams of liquid are successivelyand intermittently maintained in different fixed angular directions froma position at an interior wall surface of a pool to sweep and agitatedirt settling at or near said surface, and to move it and keep it insuspension in the pool liquid. The pool liquid is filtered therebyremoving dirt from the pool. According to another aspect of thisinvention, a plurality of jet streams is maintained at differentpositions, and the jet streams are intermittently and successivelyoperated so that at least one of the jet streams is maintained on whileanother is maintained off.

This application is a eontinuation-in-part of my copending applicationSer. No. 637,608, filed May 10, 1967, for Method and Apparatus ofCleaning a Pool, now abandoned which is a continuation of my co-pendingapplication Ser. No. 507,607, filed Oct. 22, 1965 for Method andApparatus of Cleaning a Pool, now abandoned which in turn is acontinuation-in-part of my co-pending application Ser. No. 291,885,filed July 1, 1963, for Method of Cleaning a Swimming Pool, nowabandoned.

This invention relates to the cleaning of swimming pools, and has for anobject to clean a pool automatically and efficiently.

A related object is to carry out the automatic cleaning without stainingthe pool.

It has long been a problem in cleaning swimming pools to remove thesediment and solid particles which settle from the water and accumulateon the floor and sides of a swimming pool. Surface skimming operationswill not remove it; nor is the common operation of recirculating thewater from a drain in a pool through a filter and back into the pool,effective in the absence of a method of keeping the dirt in suspension.

Attempts have heretofore been made to automatically activate the waterat the bottom of a pool to stir up the dirt particles and keep them insuspension. One method has been to mount nozzles on the sides of thepool aimed toward the drain to direct a high velocity stream of wateralong the surface of the pool toward the drain at the bottom. The highvelocity stream of water forces the dirt particles into suspension andmoves them toward the drain. This method has disadvantages, however. Thewater upon leaving the fixed nozzles must have enough momentum to send acurrent of water to the drain at the bottom of the pool. The amount ofwater flow necessary to create the required momentum is greater than theamount needed to adequately filter the pool by consecutive dilution.Therefore, a larger pump and filter are required to operate such asystem than are normally required for pool clean- Anotherdisadvantageous factor in the use of such a system resides in the factthat pool water normally con- 3,506,489 Patented Apr. 14, 1970 tainssubstances in a dissolved state as well as in suspension. Such dissolvedsubstances can include copper sulphates, iron oxides and acids used inpurifying the water. When they are played along the surfaces of the poolfor long periods of time in a fixed path of flow, they will causestaining of the pool surface.

Other proposals for automatic cleaning have involved the use of movingelements such as water hoses which move and whip around the bottom ofthe pool. Such moving objects in a pool have obvious disadvantages ofunsightliness and interference with swimming.

Another system proposed has involved the use of rotating nozzles fromwhich water jets are ejected, the rotational force on the nozzle beingderived from the same flowing water which is ejected from the nozzle.Whatever area of the pool floor or wall is reached by the jet will besubjected to its cleaning action. Typical of these are the arrangementsshown in Miller Patents 3,247,968 and 3,247,969, both issued Apr. 26,1966, involving the use of a nozzle device which is constantly rotatedby water pumped into it and ejected from a pair of nozzles offset fromthe axis of rotation.

Such rotating nozzle arrangements have the inherent disadvantage thatthe torque applied to the nozzle pair, if sufficient to overcome thefriction of the rotating nozzle member at its bearing and in rotatingthrough the pool water, must be so great as to produce an undesirablyhigh speed of rotation of at least the order of about 10 revolutions perminute. The reason for such a high rate of rotation being undesirable isthat the water jet exiting from the orifice of the rotating nozzle intothe pool is forced into a spiral path in the pool. This follows from thefact that once the jet has been ejected from the nozzle into the poolwater, the jet cannot move sideways through the pool water, and hencecannot extend radially from the axis of rotation like the spokes of awheel. Since any given rate of flow through a nozzle produces a jetstream of a limited effective length through the pool water, it isapparent that the faster the nozzle rotation, the tighter and morecompact will become the spiral of the jet, thereby resulting in asmaller area of the pool wall or floor surface which can be swept by thejet.

It is seen from the foregoing discussion that in order to obtainefficient cleaning of swimming pool wall and floor surfaces by rotatingwater jets, the jet should extend radially outward from the axis ofrotation, like a spoke of a wheel. This could be accomplished if therate of rotation of the nozzle be made slow enough, such as the order ofabout one revolution per hour. This would be in effect as though thenozzle were substantially stationary in any one direction, and such veryslow rotation might be accomplished by some sortjof electric servo orclock mechanism adequately waterproofed and attached to the nozzle inthe pool and operated by an outside source of electric power. But fromthe standpoint of economics and complication and technical difficultieswith such immersed equipment, it is not practical in a pool. Theonlypractical source of power for moving a nozzle immersed in a pool is thepumped water which is to create the jet from the nozzle.

My experimental work with a device like that of the Miller patents hasshown that the nozzles cannot be made to rotate at a speed of less thanabout ten revolutions per minute, when there is any rotation at all, andtherefore cannot avoid the undesirable spiraling, which results in anundesirable small area which can be swept by the jets.

I have attempted to overcome the disadvantage of rotating nozzles likethat of the Miller patents, by provision of a single nozzle directedradially from the axis of rotation, the turning force of which wasprovided by a relatively small orifice through the side of the nozzlewhich produced a small water jet extending from the nozzle in adirection perpendicular to the direction of the nozzle and to the axisof rotation. This small driving jet rotated the nozzle, but whenever theforce of the driving jet was sufficient to produce any rotation at all,the rotation could not be caused to be less than about ten revolutionsper minute, and for the same reasons as in the case of the Miller patentdevices. Further experiments with a pair of such nozzles oppositelydirected and with their axes passing through the axis of rotation,failed to produce rotation any slower than revolutions per minutewhenever rotation was produced at all. Furthermore, the rotational speedcould not be reduced by use of such expedients as provision of a needlebearing to reduce bearing friction and shortening the nozzles as much aspossible to reduce friction from the pool water.

Following my above-mentioned experiments with rotating nozzles, I haveheretofore proposed to overcome the above-noted difficulties anddisadvantages in the use of rotating nozzles by rotating the nozzles bymeans of a water-driven Pelton wheel connected to the nozzles through atrain of reducing gears. Such an arrangement is shown in my copendingapplication Ser. No. 637,608, filed May 10, 1967. It was hoped that thisarrangement would allow the speed of rotation of the rotating nozzles tobe slowed down to an acceptable speed so that the direction of the waterjet would be straight out from the exit nozzle and not undergo anyperceptible spiraling effect, such as incurred in the case of the Millerpatent arrangements while allowing the Pelton wheel to rotate fastenough to avoid stalling due to friction and also to accomplish theabove objectives without undue pressure loss.

Upon building and testing such a device in which the gear reductiontrain had a ratio of about 1500zl, I found the rotating nozzle could notas a practical matter be slowed down to less than /2 revolution perminute which was not sufficiently slow to eliminate the spiraling effectof the water jet to an acceptable level. The reason the Pelton wheeldevice was not practical was a combination of the spiraling effect ofthe water jet and high head loss through the Pelton wheel and orificesrequired to make the unit function. Experiments with this Pelton wheeldevice indicated that in order to obtain a desirable speed of nozzlerotation of about 1 revolution per hour or less which would produce acleaning effect from the water jet of about 7 feet, it would benecessary to provide a gear train between the nozzle and Pelton wheelwith a considerably higher gear reduction ratio than the 1500:1 ratiowhich was actually tried out. The use of such a high ratio gear trainwould be excessively expensive and would increase the pressure dropthrough the mechanism thus making this application impractical.

Exeprience has shown that in order to achieve practical and effectivecleaning of the wall or floor surfaces of a pool, about fifteen totwenty-five gallons per minute of water should be ejected from thenozzle. As the flow through the nozzle is reduced below fifteen gallonsper minute, the length to which the jet extends through the pool waterdecreases rapidly, and as the flow is increased above twenty-fivegallons per minute, the resulting increased fiow is so small as to benot worthwhile, as the length of the jet does not increase appreciablywith the increased fiow above twenty-five gallons per minute.

In the tests experiments No. silica sand of 3 /2 mm. diameter, wasspread on the pool areas to be cleaned. Loam soil and the heavier adobetype soil were also used, as was charcoal which was a lighter testmaterial. Sand is the most significant test material as sand exists inall soils and invariably falls in a swimmng pool as blow sand, and it isat least as difficult to sweep with the jet as any other of the usualmaterials to be agitated into suspension in the pool water forfiltering. In the case of the Miller patent devices and the experimentswith rotating nozzles discussed above, the maximum cleaning radius wasfound to be about three feet.

The arrangement of my present invention overcomes the above-stateddisadvantages of such rotating nozzle devices as those of the saidMiller patents and of the Pelton wheel with the gear train. Furthermore,it provides a method of cleaning the surfaces of the side walls andfioor of a pool automatically, without the use of moving 'water hoses orconduits or an excessive amount of water flow or filter capacity, andwithout staining the pool. Basically my present invention involvesdirecting the jet in a number of different angular directions from thenozzle for finite periods of time in each direction.

In accordance with my present invention, I am able to produce thedesirable effect of a very slowly rotating nozzle of the order of 1revolution per hour or less, and with a flow from the nozzle of as muchas 25 gallons per minute and a straight radially extending jet of 7 feetor more which is the radius of the surface being cleaned, while avoidingany sticking or stopping of any rotating clement. Furthermore, this isaccomplished by use of the water which fiows to the nozzle from whichthe jet emanates.

By suitable timing mechanism, the length of time of the jet in any onedirection can be adjusted as desired. Thus, a jet may be sent in eachdirection for an appreciable period of time. It is not generallypractical to send the jet in any one direction for a period of time lessthan about one-half minute. A water jet sent from the nozzle into a poolof water does not immediately reach out to a point near its full extentin less than onehalf minute. Even after a time of one-half minute, thejet will still continue to reach out slowly in the same direction up toabout three minutes. After the three minute period any further extensionof the jet in that direction becomes relatively slight. Accordingly, itmay be stated that the finite time for the jet in each of its appointeddirections should ordinarily be between onehalf and three minutes,although there is usually no harm in extending the time beyond threeminutes.

After the finite time period has expired in any one jet direction, thejet is caused to be sent in its next appointed direction for anotherfinite period of time and so on until the jet has been sent in all ofits appointed directions from the point of origin of the jet. Forexample, if the jet is to sweep a complete circle, and assuming that itwill have eighteen different appointed directions uniformly spaced, theadjacent ones of the established directions will be 20 degrees apart,and if the system is timed to send the jet in each of its directions forthree minutes, it will take about fifty-four minutes for the jet tocover the entire circle, assuming that the time interval between thesuccessive jets is not appreciable.

In the case of most pools, I prefer to use more than one of these jets,which will be spaced apart from each other by proper distances to insurethat all parts of the pool are acted upon by the arrangement of waterjets.

In the operation of this cleaning method, one or more of the water jetswill ordinarily be maintained substantially all the time during thenormal filtering of the pool. Thus, dirt will be maintained insuspension in the pool water and filtered out through the pool filter inthe usual manner.

The cleaning method can readily be carried out by means of suitablefittings attached to the bottom and side walls of the pool and connectedwith a system of water under pressure, ordinarily the pool filteringpump, to produce the water jets.

A desirable, but optional, feature resides in the location of a jetdevice at the position of a drain of the pool.

According to a feature of the invention, the angular direction of a jetis shifted from one of its established angular directions to the nextdirection by action of the water itself which is brought to thejet-producing nozzle. A related feature resides in the use in a waterconduit leading to the jet nozzle device of a valve means effectiveintermittently to shut off and turn on the flow of water to the nozzledevice, thereby causing the shift of nozzle direction by means of thesewater flow discontinuities.

A further related feature resides in the use of a valve mechanism whichreceives the pumped or pressurized water which is to be sent to the jetnozzles and directs it first to one jet nozzle device for a finiteperiod of time to shift its jet direction and establish the finite timeof the jet in that direction, and then shifts the water flow to anotherjet-producing nozzle to shift its jet direction and establish the finitetime of its water jet.

This last-mentioned feature has the advantage of allowing water from apool to be pumped through a filter and then alternately into the waterline to one jet-producing device followed by introduction into the waterline to a second jet-producing device. This allows two separate waterlines to be operated alternately and with the full flow attainable froma given sized pump and filter. If it were attempted to supply both waterlines at the same time with the same water flow there would be requiredan extra capacity pump and filter which would involve further expense.

The foregoing and other features of the invention will be more readilyunderstood from the following detailed description and the accompanyingdrawings of which:

FIG. 1 is a plan view of a rectangular shaped swimming pool equippedwith water fittings to'produce water jets according to this invention;

FIG. 2 is a section View taken at line 44 of FIG. 1;

FIG. 3 is a plan view of a kidney shaped swimming pool equipped withwater fittings for producing the cleaning action;

FIG. 4 shows a partially cutaway view of a swimming pool provided with apumping and filtering system and with outlets into the pool, some ofwhich provide jets in the form of intermittent jets sent in differentangular directions;

FIG. 5 is a View partially in cross-section at the main drain of theswimming pool of FIG. 4;

FIG. 6 is a view partially in cross-section of a timed valve used in thesystem of FIGS. 4 and 7;

FIG. 7 shows another partially cutaway view of a swimming pool with afiltering and pumping system and with a different arrangement of outletscomprising intermittent water jets; and

FIG. 8 shows a modification of the arrangement of FIG. 5.

FIGS. 1 and 2 show water fittings such as fittings 10 connected to watermain 16 by pipes 16a and mounted into the side walls and floor of arectangular shaped pool, the side walls and floor being herein referredto as the swimming pool walls or surfaces. The main and pipes arerepresented by the lines, and the arrows in the lines represent thedirection of water flow. It is preferred that top 13 of casing 11 belevel with the inner wall and floor surfaces of the pool. Each of thefittings causes a water jet to flow over a surface area having aperimeter denoted by dotted lines 61. By proper positioning of the jetdevices or fittings in the walls and floor of the pool, substantiallythe entire surface of the pool is covered. The curved edges and cornersof the pool change the direction of water flow denoted by arrows 62 asshown in FIG. 2.

It is desired that the water jet is not shot above the water surface 63of the pool. Hence, the fittings are disposed sufficiently below thesurface of the water so that the jet of water will not have enoughmomentum to shoot above the surface. It may be desired that the fittingson the side wall surfaces have small orifice openings, or the waterpressure at their inlets may be low in comparison to the water pressureat the fittings on the floor of the pool so that the momentum of thewater leaving the wall fittings will be smaller than that on the floor.This will allow the floor fittings to have a greater coverage than thewall fittings and the wall fittings will not shoot a jet of water out ofthe pool when the head rotates to the position of a vertically directedjet of water.

As the water current moves over the floor and/or wall surfaces of thepool, solid particles of dirt and debris lying on said surfaces areforced by the current back into suspension in the water. A drain 64 atthe bottom of the pool allows the water to drain from the pool tocirculate through a filter 65 and a pump 66 back to the water fittings10. The filter operates to clean the water of the suspended solidparticles and the pump then pumps the water back to the fittings.

FIG. 3 shows a kidney shaped pool 69 with water fittings 10 mounted inthe walls and floor of the pool in a similar manner as previouslydescribed in connection with the rectangular shaped pool. In this case,however, the positioning of the fittings in the sides and bottom of thepool will generally be different from that of the rectangular shapedpool due to the curvature of the walls.

The positionings of the fittings in FIGS. 1 and 3 are only shown asexamples of the method of cleaning the pool and it must be understoodthat the positioning is entirely arbitrary. The positioning will dependupon such factors, for example, as the depth of the water of the poolwhere the fitting is placed, the effective coverage of the fitting, thelocation of the steps, or other obstacles in the pool.

FIG. 4 shows another arrangement for cleaning a swimming pool by actionof water jets, which in this case involves the use of intermittent jetsof water which are successively directed in different angular directionsfrom the position of the jet. The swimming pool is shown with its wallpartly broken away for illustration of the parts. According to commonpractice, the main drain 91 of the pool is located at its lowermostposition in the pool, through which water is withdrawn from the bottomof the pool through pipe 92 and drawn by a motor-operated pump 93through a suitable strainer 94 which removes debris before entry of thepool water into the pump. The pump sends the pool water into a filter 95through pipes 96 and 97. At the same time the pump draws water through apipe 98 from a skimmer 99 located at the surface of the pool water."Because of the fact that the pool walls are shown broken away at theregion of the skimmer, its attachment in the pool wall is not shown. Theskimmer can be of a well-known type needing no detailed descriptionhere, and may be constructed for example as shown in US. Pataent No.3,067,879, issued Dec. 11, 1962. Its elevation at the pool wall is suchthat the normal pool water level is about half-way up the entrancepassageway 100 of the skimmer, through which it is drawn to pass througha suitable debris-collecting basket (not shown herein, but illustratedin said Patent No. 3,067,879) located within housing 101 from where itpasses through pipe 98 through the strainer 94 to the pump. The pumpwater delivered from the output of the filter passes through a pipe 102to a motor driven selector valve 103 which may be constructed as shownin FIG. 6.

The selector valve comprises a generally cylindrical housing 104providing an internal compartment 105 within which is fitted a valveshaft 106 concentrically located within the cylinder and mounted in asuitable bearing supported by webs 107 fixed to the housing. The shaftcarries a valve gate in the form of a half cylinder 108 supported by asolid portion or web 109 fastened to the shaft. This gate makes slidingcontact with surfaces 110a, 1101;, 1100 and 110d formed as parts of acylinder centered at the shaft and acting as valve seats. Between seats110a and 110d there is an outlet port 111 leading to an outlet section112 which threads to a pipe 113. Op-

posite port 111 there is a similar outlet port 114, located betweenseats 11% and 1100, leading to an outlet section 115 which threads to anoutlet pipe 116. At the bottom of chamber 105 there is an inlet port 117opening downwardly into a section 118 which is threaded to pipe 102. Theupper parts of the housing and chamber 105 are closed by a top closure119 to which there is attached a motor 120, the shaft of which attacheswith the shaft 106 of the valve. The motor 120 is of the slow drivetype, made slow by means such as gears (not shown) which causes rotationof the shaft 106 slowly so that the valve member 108 intermittently andsuccessively closes the ports 111 and 114, the lower port 117 alwaysbeing open. Thus, water is always free to enter the chamber 105 throughport 117 and to be emitted from the chamber 105 either through port 111or port 114.

A pipe T 121 is fitted to pipe 116, and from this T there are broughttwo pipes 122 and 123. The pipe 122 is connected to a jet-producingdevice 89 located within the main drain 91 in the fioor of the pool asshown in FIG. 5. This jet-producing device is of a character which sendsa jet of water in a certain direction laterally along the surface of thepool floor, when the valve port 114 is open. Each time the valve portopens after being closed, the jet is sent in a different lateraldirection. Thus, successive water jets each in a fixed direction aresent from device 89 in successively different angular directions, aroundthe device 89. Details of construction and operation of the intermittentjet-producing device 89 are given in the co-pending application of DavidA. Stanwood, entitled Liquid Jet Producing Device, Ser. No. 500,583,filed Oct. 22, 1965, now US. Patent No. 3,408,- 006, granted Oct. 29,1968, and assigned to the same assignee as the present application.

The pipe 123 is carried around the outside of the pool wall to an outlet125 located in a side wall somewhere below the water surface the outletbeing of a type provide with a directional deflector 126 which ispreferably adjustable. This functions to send the water into the pooland by proper adjustment can be sent in any desired direction, forexample, laterally to sweep along the side wall. This will tend tocirculate the water around the pool. A branch pipe 127 is led off frompipe 123 by a T 128, pipe 127 leading to another outlet 129 at the floorof the pool at some distance from the main drain 91. The outlet 129,carried up through the concrete bottom wall of the pool, can be the sametype of jet-producing device as the device 89 of FIG. 5.

The pipe 113 is brought to still another location at the outside of thepool where it is brought to an outlet 130 at the side wall of the pooland provided with a baffle or deflector 131 to send the water output ina desired direction such as tangentially along the pool wall, preferablyin the same direction around the pool as provided by outlet 125. A T 132placed in line 113 provides for a branch pipe 133 which leads to anotheroutlet 134 which is in the floor of the pool at a shallower part of thepool than at the main drain and at some distance from outlet 129 andfrom the main drain 91. Outlet -134 is of the same jet-producing type asoutlets 129 and 89.

The main drain 91 is, according to common practice, in the form of achamber 135 formed within the bottom wall 136, ordinarily of concrete,at the deepest part of the pool. This chamber 135 is, according tocommon practice, of a cylindrical shape and provided a circular bottom137 through which pipe 122 extends and is sealed by the cement toprevent leakage between the exterior of the pipe and the concrete.Around the open top of the chamber 135 there is fitted to the concretewall an annular ring 139 whose internal diameter is the same and flushwith the internal diameter of the chamber 135; and this ring has anupstanding cylindrical portion 140, the top of which is flush with theupper surface 138 of the bottom wall of the pool. In most pools, a gratein the form of a circular member will be fitted within the member 140resting on the ring 139. In the present situation, however, such a grateis dispensed with and instead, the upper open end of chamber is coveredby the water jet-producing device 89 and its mounting member 141. Themember 141 comprises an annular ring portion 142 mounted on a number oflegs 153 spaced apart from each other around the annulus and resting onthe ring 139 and in contact with the ring as shown. The legs 143 aretall enough to hold the ring 142 at some distance above the surface 138of the concrete so that there is ample space for communication betweenchamber 135 and the water of the pool. Thus, water drained from thismain drain through pipe 92 will flow from the pool into chamber 135through these spaces between adjacent legs 143. The inner portion of themember 142 is formed as a circular bracket 144 which rests against anouter peripheral rim 145 of the housing of the water jet-producingdevice 89. Extending upwardly from the rim 145 there is provided a cap146 provided with a number of spaced ports 147 separated equidistantfrom each other and directed in successively different angulardirections all around the 360 periphery of cap 146. Each of these ports147 communicates with an interior chamber of device 89 which receiveswater being pumped into the pool through pipe 122.

Since the particular jet-producing device 89 is that shown in theabove-mentioned co-pending application Ser. No. 500,583, filed Oct. 22,1965, of David A. Stanwood, assigned to the same assignee as the presentapplication, it need not be described here in detail. It is sufiicientto say that the internal mechanism of this device provides that whenwater is introduced into this device through pipe 122 under pressure,the pressurized water will squirt out of one of the ports 147horizontally along the bottom surface of the pool in the direction towhich the port is directed. Then when the pressure is shut off, the jetof water will cease, but the next time the pressure is turned on, thejet of water will be directed out through the next adjacent port in asomewhat different angular direction. In this way, as the water in pipe122 is intermitently turned on and off, the jets of water from the ports147 will be emitted from successively different and adjacent ports allaround the perimeter of the device 89.

Each of the jet-producing devices 129 and 134 will operate in the sameway as device 89 when pressurized intermittently by the water pressure,a difference of devices 129 and 134 from device 89 being that devices129 and 134 are not associated with any drain from the pool. Instead,the housing of the jet device can be cemented into the pool wall,leaving the ports 147 exposed to produce the jets in the pool.

Where the jet device is placed at the main drain as in FIG. 4, theaction will be somewhat different than at other positions such as withdevices 139 and 134. At the main drain, the fast jet emitted from a port147 passing horizontally over plate 142 and into the pool water willcreate a reduced pressure at the region below plate 142 and at thespaces between legs 143, thus tending to facilitate the passage of waterinto the main drain.

FIG. 7 shows an arrangement of water outlet devices in a swimming poolsomewhat different from that shown in FIG. 4. In FIGS. 4 and 7 the sameparts are designated by the same numerals. FIG. 7 differs from FIG. 4 inthat in FIG. 7 the main drain 91 does not contain any waterjet-producing device 89. Instead, the main drain simply comprises achamber 135 covered by a circular grated cover plate 148 through thespaces of which the water can flow from the pool to the chamber 135.There are, however, in FIG. 7 the jet-producing outlets 129 and 134, thesame as in FIG. 4 Likewise, in FIG. 7 there are the side wall outlets125 and 130 directionally baffled in a manner similar to that in FIG. 1.

To operate the system of FIGS. 4 and 7, the motor M is powered by asuitable electric power line (not shown) which operates pump 94 to drawwater from the pool through the skimmer 99 through pipe 98 and at thesame time from the main drain 91 through pipe 92, this water drawn fromthe pool being controllable by hand valves in a well-known manner.

The water after being cleaned by strainer 94 is pumped into the filter95 where it is cleaned and purified and sent into the outlet line 102 tothe inlet port 117 of valve 103. The motor 120 for rotating the valvemember 108 can be powered from the power line and adjusted and geared torotate the valve at any desired rate, for example from a fraction of aminute to several minutes or more per revolution. During about half thetime of rotation of the valve member, the valve port 111 will be closedby the valve and during the other approximate half time the other valveport 114 will be closed. Whenever one of the ports is closed the otherport will be open, so that the water entering the valve chamber at 105will pass out through the open one of the ports to be sent into eitherpipeline 113 or pipeline 116.

When valve port 114 is open, the pressurized water in line 116 will besent into pipe branch 122 to pressurize the jet device 89 (and 129),which will send a jet of water out through one of their ports 147, alongthe bottom wall of the pool for as long a time as valve port 114 isopen; and at the same time outlet 125 will deliver to the pool. Whenport 114 then closes while port 111 is open, the water jet will be shutoff at device 89 (and 129) and will be turned on at jet device 134; andcorrespondingly, a jet of water will be directed out one of the ports ofdevice 134 along the surface of the pool floor in the vicinity of thatdevice; and of course, outlet 130 will be delivering in its establisheddirection.

Referring to FIG. 7, since there is no jet-producing device in the maindrain of this arrangement, all of the water jetting which occurs at thefloor of the pool will be due to the two jet devices 129 and 134.

When the rotary valve has turned sufficiently to open its port 114again, while port 111 is closed, the jet devices 89 and 129 will againbe operative. But by reason of the mechanism within the jet device, asnoted above and explained in detail in said co-pending Stanwoodapplication, the jet will this time be directed out of the port 147which is adjacent to the port from which the preceding jet had beenemitted; and this second port will be at a somewhat different anglefrom' the first port. The jet from the second port will then be on for aperiod of time. This action of alternating the water pressure from ports111 and 114 of the valve will result in successive intermittent jetsfrom the jet-producing devices, and each successive jet will be at adifferent angle around the horizontal circle.

The side wall inlets 125 and 130 into the pool, when directed by theirbaffles as shown in FIGS. 4 to 7 along the side walls, will circulatethe water around the pool while the jet devices 129 and 134 in thebottom Wall or floor of the pool are sending out their jets. Thiscombination of jetting the water along the bottom while at the same timecirculating the water in one direction around the side walls of the poolhas an especially salutary effect in cleaning the pool which is muchmore effective than the mere sum total of the effects of the bottom walldevices and the side wall devices separately. The water jets at thefloor, either of the continuous type or the intermittent type describedhereinabove, will move the undesired solids into different sections ofthe pool from the location of the jets. Some of the solids go intosuspension or move up above the pool floor and may find themselves inremote spots such as corners of the pool, while other parts of thesolids are swept more directly toward the main drain (by jet deviceslocated away from the drain). Those parts of the solids which tend tolinger along the sides or remote corners are moved by the water beingcirculated due to the action of the outlets 125 and 130 in the sidewalls, thus being carried around the pool to the surface skimmer in thecase of those which remain at the surface. In the case of matter insuspension or floating in the pool water which is not carried to theskimmer, this circulating action will still have the effect of causingit ultimately to fall or be moved into the main drain.

FIG. 8 shows an arrangement of a jet device at a main drain which can beused in lieu of that shown in FIG. 5. Like numbers in FIGS. 5 and 8represent similar parts. In FIG. 8, chamber 135 for the sump or maindrain is encased by a metal container 150 which can be fitted into theconcrete of the pool flOOr (not shown). Within the chamber there is ajet device 151 which can be of a type similar to device 89 of FIG. 5.Instead of introducing a drain pipe in the manner of the pipe 92 of FIG.5, the side wall of member 150 is rounded or bulged at 152 at one sidenear the bottom thereof; and into this bulge there is threaded the drainpipe 92. The principal difference in the arrangements of FIGS. 5 and 8is that in the arrangement of FIG. 8, the drain water is drawntangentially out of the sump chamber 135, which draws water evenly andwithout vortexing from along the pool floor through the spaces 144between the legs which hold member 144 raised above member 150, carryingdirt with it; and by imparting a rotating movement lower down in thesump near the drain pipe.

It will be recognized that as many water jet devices and also sideoutlets may be placed in the pool as may be desired, dependingconsiderably on the size and dimensions of the pool. A smaller pool willof course have fewer water outlets than a larger pool. Thus thearrangement of FIG. 7 will usually be for a smaller pool than thearrangement of FIG. 4.

The arrangements of FIGS. 4 and 7 can be set up to take any desiredlength of time for the water jets to ocour all around the 360 of thejet-producing device, and thus the desired amount of time and cleaningin any one direction from the jet device can readily be set up.

It will be recognized that the selector 103 is not limited to the twooutlet ports which are shown. It may have any greater number of outletports as may be desired, and each outlet port may be connected tocorresponding outlets in the pool.

It should be understood that the practice of the invention is notlimited to the use of the particular fittings shown in the drawings,which are illustrated simply to show forms of fittings which could beused.

Other water jet fittings than those illustrated in FIGS. 4, 5 and 7 maybe developed or used and the invention is not limited to the use ofthese particular structures. Furthermore, it is not essential that thewater jets be sent step by step through a full 360 at each jet position.For example, stepping back and forth within a segment of a full circle,would be possible.

In this specification and appended claims it should be understood thatthe term wall, unless otherwise stated, is broadly used to cover any ofthe interior surface walls of the pool, whether horizontal floor wallsor vertical side walls.

The invention is not limited to the particular arrangements and methodsillustrated and described herein, which are given by way of illustrationrather than of limitation, and the invention is not limited except inaccordance with the scope of the appended claims. It is particularlynoted that the term pool as used herein is not restricted to swimmingpools nor to the use of water, but broadly covers other forms ofcontainers for Water or other liquid.

What-is claimed is:

1. The method of cleaning the interior wall surface of a pool containingliquid which comprises successively maintaining individual ones of aplurality of straight-line jet streams of liquid for successive periodsof at least onehalf minute each in different fixed angular directionsfor a substantial distance from a position at said wall within the poolto sweep and agitate dirt settling at or near said surface, to move thedirt and keep it in suspension in the pool liquid, and filtering theliquid of the pool to remove 1 1 the dirt from the pool liquid, thedifferent directions being separated by a finite angle.

2. The method according to claim 1 wherein the individual jet streamsare successively and intermittently maintained by directing andmaintaining a first of the jet streams in a fixed straight-linedirection for at least one-half of a minute from a position adjacentsaid surface and directed along the wall surface, and then directing andmaintaining a second of the jet streams for at least another one-half ofa minute from said position in a fixed straight-line direction angularlydifferent from the direction of the first jet stream and withoutrotation of the jet stream.

3. The method according to claim 1 wherein a liquid jet stream projectorcapable of emitting a jet stream is at said position adjacent said wallsurface, said projector having selection means for selecting individualones of a plurality of fixed directions from which the jet stream isemitted, said method further comprising selecting a first fixeddirection of said projector, emitting a first jet stream of liquid fromsaid projector in said first fixed direction along said surface for atleast one-half of a minute, then selecting a second fixed direction ofsaid projector by action of the liquid flow which will form the jetstream, and emitting a second jet stream from said projector in saidsecond fixed direction along said surface for at least one-half of aminute.

4. A method according to claim 1 in which said jet stream is at thefloor of a pool and liquid is emitted into the pool at a side wallthereof in a direction laterally along said side wall to circulate wateraround the pool, and skimming off some of the circulating water at thewater at the water surface, whereby dirt existing or sent to said sidewall is removed from the pool.

5. The method of cleaning water in a pool which comprises intermittentlymaintaining individual ones of a plurality of straight-line jet streamsof water in fixed direc tions from a first position at a wall surface ofthe pool, intermittently maintaining individual ones of a plurality ofstraight-line jet streams of water in fixed directions from a secondposition at the wall surface of the pool, each jet stream beingmaintained for at least one-half minute, and intermittently andsuccessively operating said jet streams so that a jet stream ismaintained for at least one-half minute from said first position whileno jet stream is maintained from the second position and so thatsubsequently a jet stream is maintained for at least onehalf minute fromthe second position while not jet stream is maintained from the firstposition, and continuously filtering the pool water.

6. The method according to claim 5 in which said jet streams are at thefloor of the pool and water is emitted into the pool at a side wallthereof in a direction laterally along said side wall to circulate wateraround the pool, and skimming off some of the circulating water at thewater surface, whereby dirt existing or sent to said side wall isremoved from the pool.

7. The method according to claim 5 further including intermittently andsuccessively altering the direction of the jet stream at each positionby action of the water flow which is to constitute the jet stream.

8. The method according to claim 1 wherein said plurality of jet streamsare maintained from such positions in said pool that all of said jetstreams together sweep and agitate dirt from substantially the entirewall surface area of the pool below the liquid level in the pool.

9. The method of circulating and cleaning the water in a swimming poolwhich comprises pumping the water out of the drain located at the bottomwall of the pool, filtering the water, and subsequently pumping it intothe pool in a straight-line jet stream maintained for at least one-halfminute in a fixed straight-line direction substantially parallel to awall surface of the pool at the floor thereof from a positionimmediately above the drain, and intermittently and sequentiallyaltering the direction of the jet stream by action of the water flowwhich produces the jet stream to successive fixed straightlinedirections for finite periods of time of at least onehalf minute each,all of said jet streams together being directed from said position toclear dirt from an area surrounding said drain in a 360 arc around saiddrain, whereby water being pumped out of the pool flows into the drainbeneath the position of the origin of the jet while the jet stream isflowing.

10. In combination with a pool: means for drawing water out of the pooland filtering it, means for returning filtered water to the pool, saidlast named means including a conduit, a water projecting means attachedto said conduit and located at a position adjacent the wall surface ofthe pool, said projecting means comprising a plurality of outlets whichdirect water jet streams in different respective angular directions fromthe projecting means along said wall surface, means connected with saidprojecting means and operated by discontinuity of the water flow throughsaid conduit for shifting the jet stream from one to another of theoutlets, and intermittent means at said conduit for intermittentlyreducing the water flow through said conduit thereby producingdiscontinuities of water flow which shift the jet stream from one outletto another, said intermittent means producing discontinuities atintervals of at least one-half minute.

11. Apparatus according to claim 10 further including a second waterprojecting means located at a second position adjacent the wall surfaceof the pool, said second projecting means comprising a plurality ofoutlets which direct water jet streams in different angular directionsfrom the second projecting means along said wall surface, second conduitmeans connecting said second projecting means to said intermittentmeans, and means connected with said second projecting means andoperated by discontinuity of the water flow through said second conduitfor shifting the jet stream from one to another of the outlets at saidsecond projecting means, said intermittent means successively directingwater fiow first to the first-named conduit and then to the secondconduit, whereby the intermittent means successively directs water tosaid conduits for periods of at least onehalf minute.

12. Apparatus according to claim 10 further including a drain within thepool, said drain comprising a chamber located in the pool floor, saidmeans for drawing water out of the pool being adapted to draw water outof said chamber, said water projecting means being located above saidchamber and somewhat above the level of the floor, all of the jetstreams together being capable of clearing dirt from a 360 are aroundsaid chamber.

13. Apparatus according to claim 12 in which a drain pipe is fittedtangentially into said chamber to create a rotating motion of water intothe chamber near the drain pipe as it is being drained out, thuscollecting water uniformly and without vortex at the entrance to saidchamber.

References Cited UNITED STATES PATENTS 3,045,829 7/1962 Rule et al.210-169 3,247,968 4/1966 Miller 210l69 X 3,247,969 4/ 1966 Miller210-169 SAMIH N. ZAHARNA, Primary Examiner US. Cl. X.R.

1:1 3'" UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,506,489Dated April 14, 1970 Patent No.

Invencor(s) am 0. Baker It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

[- Column 3, line 56 "Exeprience" should be --Experienceline 68 "the"should be --these- Column 4, line 37 "time has been left out --timeperiod-- Column 8, line 7 "153" should be "143-- Column 11, line 33 "atthe water" in twice line 49 "not"shou1 d be --no-- SIGNEEMD SHED Amen

w 1!. member, Ir.

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00111115510110:- of Patents

